<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>const常量</title>
</head>
<body>

</body>

<script>
    //const 使用常量关键词声明，声明后必须赋值，声明后不能修改值
    const  PI = 3.14;
    console.log(PI);
</script>
</html>